Will the non power Drum prop valve, and the Power Drum prop valve be the same on a 72 cutlass?? Not sure if the valve is just different for disc/drum set ups. May just be one less thing I have to take off.

Thanks

 

Four wheel drum brake systems do not use proportioning valves. They have a distribution block that simply houses the differential pressure valve that illuminates the BRAKE light on the dash if one side of the system looses pressure. There is no front/back proportioning at all. The distribution block is identical for power and non-power brakes.